<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>监听器语法</title>
</head>
<body>
    <script src="../js/vue.js"></script>
    <div id="app">
        <p>{{val}}</p>
    </div>
        
    <script>
     var vm = new Vue({
        el:"#app",  
        data: { 
            val:"复杂对象初始值",
            obj:{
                name:"复杂对象name",
                value:"复杂对象",
            } 
        } ,
        watch:{
            val:function(newval,oldval){
     console.log(newval,oldval);
            consloe.log(this.val)
            },
            obj:{
                deep:true,
                handler:function(new_val,old_val){
                    console.log(new_val,old_val)
                }
            }
        }
     }) 
    </script>
</body>
<html>